/*
  * Cinepak Video Decoder

  * Copyright (C) 2003 The FFmpeg project

  *

  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

  * version 2.1 of the License, or (at your option) any later version.

  *

  * FFmpeg is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public

  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  */
 
 /**

  * @file

  * Cinepak video decoder

  * @author Ewald Snel <ewald@rambo.its.tudelft.nl>
  *
  * @see For more information on the Cinepak algorithm, visit:

  *   http://www.csse.monash.edu.au/~timf/

  * @see For more information on the quirky data inside Sega FILM/CPK files, visit:

  *   http://wiki.multimedia.cx/index.php?title=Sega_FILM

  *
  * Cinepak colorspace support (c) 2013 Rl, Aetey Global Technologies AB
  * @author Cinepak colorspace, Rl, Aetey Global Technologies AB

  */
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 

 #include "libavutil/common.h"

 #include "libavutil/intreadwrite.h"

 #include "avcodec.h"

 #include "internal.h"

 typedef uint8_t cvid_codebook[12];

 
 #define MAX_STRIPS      32
 

 typedef struct cvid_strip {

     uint16_t          id;
     uint16_t          x1, y1;
     uint16_t          x2, y2;

     cvid_codebook     v4_codebook[256];
     cvid_codebook     v1_codebook[256];
 } cvid_strip;

 
 typedef struct CinepakContext {
 
     AVCodecContext *avctx;

     AVFrame *frame;

     const unsigned char *data;

     int size;
 

     int width, height;
 

     int palette_video;

     cvid_strip strips[MAX_STRIPS];

     int sega_film_skip_bytes;
 

     uint32_t pal[256];

 } CinepakContext;
 

 static void cinepak_decode_codebook (cvid_codebook *codebook,

                                      int chunk_id, int size, const uint8_t *data)

 {

     const uint8_t *eod = (data + size);

     uint32_t flag, mask;
     int      i, n;

     uint8_t *p;

 
     /* check if this chunk contains 4- or 6-element vectors */

     n    = (chunk_id & 0x04) ? 4 : 6;

     flag = 0;
     mask = 0;
 

     p = codebook[0];

     for (i=0; i < 256; i++) {

         if ((chunk_id & 0x01) && !(mask >>= 1)) {

             if ((data + 4) > eod)
                 break;
 

             flag  = AV_RB32 (data);

             data += 4;
             mask  = 0x80000000;
         }
 

         if (!(chunk_id & 0x01) || (flag & mask)) {

             int k, kk;
 

             if ((data + n) > eod)
                 break;
 

             for (k = 0; k < 4; ++k) {
                 int r = *data++;
                 for (kk = 0; kk < 3; ++kk)
                     *p++ = r;
             }

             if (n == 6) {

                 int r, g, b, u, v;
                 u = *(int8_t *)data++;
                 v = *(int8_t *)data++;
                 p -= 12;
                 for(k=0; k<4; ++k) {
                     r = *p++ + v*2;
                     g = *p++ - (u/2) - v;
                     b = *p   + u*2;
                     p -= 2;
                     *p++ = av_clip_uint8(r);
                     *p++ = av_clip_uint8(g);
                     *p++ = av_clip_uint8(b);
                 }

             }

         } else {
             p += 12;

         }
     }
 }
 

 static int cinepak_decode_vectors (CinepakContext *s, cvid_strip *strip,

                                    int chunk_id, int size, const uint8_t *data)

 {

     const uint8_t   *eod = (data + size);

     uint32_t         flag, mask;

     uint8_t         *cb0, *cb1, *cb2, *cb3;

     int             x, y;

     char            *ip0, *ip1, *ip2, *ip3;

 
     flag = 0;
     mask = 0;
 
     for (y=strip->y1; y < strip->y2; y+=4) {
 

 /* take care of y dimension not being multiple of 4, such streams exist */

         ip0 = ip1 = ip2 = ip3 = s->frame->data[0] +
           (s->palette_video?strip->x1:strip->x1*3) + (y * s->frame->linesize[0]);

         if(s->avctx->height - y > 1) {

             ip1 = ip0 + s->frame->linesize[0];

             if(s->avctx->height - y > 2) {

                 ip2 = ip1 + s->frame->linesize[0];

                 if(s->avctx->height - y > 3) {

                     ip3 = ip2 + s->frame->linesize[0];

                 }
             }
         }
 /* to get the correct picture for not-multiple-of-4 cases let us fill
  * each block from the bottom up, thus possibly overwriting the top line
  * more than once but ending with the correct data in place
  * (instead of in-loop checking) */

 
         for (x=strip->x1; x < strip->x2; x+=4) {

             if ((chunk_id & 0x01) && !(mask >>= 1)) {

                 if ((data + 4) > eod)

                     return AVERROR_INVALIDDATA;

                 flag  = AV_RB32 (data);

                 data += 4;
                 mask  = 0x80000000;
             }
 

             if (!(chunk_id & 0x01) || (flag & mask)) {
                 if (!(chunk_id & 0x02) && !(mask >>= 1)) {

                     if ((data + 4) > eod)

                         return AVERROR_INVALIDDATA;

                     flag  = AV_RB32 (data);

                     data += 4;
                     mask  = 0x80000000;
                 }
 

                 if ((chunk_id & 0x02) || (~flag & mask)) {

                     uint8_t *p;

                     if (data >= eod)

                         return AVERROR_INVALIDDATA;

                     p = strip->v1_codebook[*data++];

                     if (s->palette_video) {

                         ip3[0] = ip3[1] = ip2[0] = ip2[1] = p[6];
                         ip3[2] = ip3[3] = ip2[2] = ip2[3] = p[9];
                         ip1[0] = ip1[1] = ip0[0] = ip0[1] = p[0];
                         ip1[2] = ip1[3] = ip0[2] = ip0[3] = p[3];

                     } else {

                         p += 6;

                         memcpy(ip3 + 0, p, 3); memcpy(ip3 + 3, p, 3);
                         memcpy(ip2 + 0, p, 3); memcpy(ip2 + 3, p, 3);
                         p += 3; /* ... + 9 */
                         memcpy(ip3 + 6, p, 3); memcpy(ip3 + 9, p, 3);
                         memcpy(ip2 + 6, p, 3); memcpy(ip2 + 9, p, 3);
                         p -= 9; /* ... + 0 */
                         memcpy(ip1 + 0, p, 3); memcpy(ip1 + 3, p, 3);
                         memcpy(ip0 + 0, p, 3); memcpy(ip0 + 3, p, 3);
                         p += 3; /* ... + 3 */
                         memcpy(ip1 + 6, p, 3); memcpy(ip1 + 9, p, 3);
                         memcpy(ip0 + 6, p, 3); memcpy(ip0 + 9, p, 3);

                     }
 
                 } else if (flag & mask) {
                     if ((data + 4) > eod)

                         return AVERROR_INVALIDDATA;

                     cb0 = strip->v4_codebook[*data++];
                     cb1 = strip->v4_codebook[*data++];
                     cb2 = strip->v4_codebook[*data++];
                     cb3 = strip->v4_codebook[*data++];
                     if (s->palette_video) {
                         uint8_t *p;
                         p = ip3;
                         *p++ = cb2[6];
                         *p++ = cb2[9];
                         *p++ = cb3[6];
                         *p   = cb3[9];
                         p = ip2;
                         *p++ = cb2[0];
                         *p++ = cb2[3];
                         *p++ = cb3[0];
                         *p   = cb3[3];
                         p = ip1;
                         *p++ = cb0[6];
                         *p++ = cb0[9];
                         *p++ = cb1[6];
                         *p   = cb1[9];
                         p = ip0;
                         *p++ = cb0[0];
                         *p++ = cb0[3];
                         *p++ = cb1[0];
                         *p   = cb1[3];
                     } else {
                         memcpy(ip3 + 0, cb2 + 6, 6);
                         memcpy(ip3 + 6, cb3 + 6, 6);
                         memcpy(ip2 + 0, cb2 + 0, 6);
                         memcpy(ip2 + 6, cb3 + 0, 6);
                         memcpy(ip1 + 0, cb0 + 6, 6);
                         memcpy(ip1 + 6, cb1 + 6, 6);
                         memcpy(ip0 + 0, cb0 + 0, 6);
                         memcpy(ip0 + 6, cb1 + 0, 6);

                     }
 
                 }
             }
 

             if (s->palette_video) {
                 ip0 += 4;  ip1 += 4;
                 ip2 += 4;  ip3 += 4;
             } else {
                 ip0 += 12;  ip1 += 12;
                 ip2 += 12;  ip3 += 12;
             }

         }
     }
 
     return 0;
 }
 
 static int cinepak_decode_strip (CinepakContext *s,

                                  cvid_strip *strip, const uint8_t *data, int size)

 {

     const uint8_t *eod = (data + size);

     int      chunk_id, chunk_size;
 
     /* coordinate sanity checks */

     if (strip->x2 > s->width   ||
         strip->y2 > s->height  ||

         strip->x1 >= strip->x2 || strip->y1 >= strip->y2)

         return AVERROR_INVALIDDATA;

 
     while ((data + 4) <= eod) {

         chunk_id   = data[0];
         chunk_size = AV_RB24 (&data[1]) - 4;

         if(chunk_size < 0)

             return AVERROR_INVALIDDATA;

         data      += 4;
         chunk_size = ((data + chunk_size) > eod) ? (eod - data) : chunk_size;
 
         switch (chunk_id) {
 

         case 0x20:
         case 0x21:
         case 0x24:
         case 0x25:

             cinepak_decode_codebook (strip->v4_codebook, chunk_id,

                 chunk_size, data);
             break;
 

         case 0x22:
         case 0x23:
         case 0x26:
         case 0x27:

             cinepak_decode_codebook (strip->v1_codebook, chunk_id,

                 chunk_size, data);
             break;
 

         case 0x30:
         case 0x31:
         case 0x32:

             return cinepak_decode_vectors (s, strip, chunk_id,

                 chunk_size, data);
         }
 
         data += chunk_size;
     }
 

     return AVERROR_INVALIDDATA;

 }
 
 static int cinepak_decode (CinepakContext *s)
 {

     const uint8_t  *eod = (s->data + s->size);

     int           i, result, strip_size, frame_flags, num_strips;
     int           y0 = 0;

     int           encoded_buf_size;

 
     if (s->size < 10)

         return AVERROR_INVALIDDATA;

 
     frame_flags = s->data[0];

     num_strips  = AV_RB16 (&s->data[8]);

     encoded_buf_size = AV_RB24(&s->data[1]);

 
     /* if this is the first frame, check for deviant Sega FILM data */
     if (s->sega_film_skip_bytes == -1) {

         if (!encoded_buf_size) {

             avpriv_request_sample(s->avctx, "encoded_buf_size 0");

             return AVERROR_PATCHWELCOME;

         }

         if (encoded_buf_size != s->size && (s->size % encoded_buf_size) != 0) {

             /* If the encoded frame size differs from the frame size as indicated
              * by the container file, this data likely comes from a Sega FILM/CPK file.
              * If the frame header is followed by the bytes FE 00 00 06 00 00 then
              * this is probably one of the two known files that have 6 extra bytes

              * after the frame header. Else, assume 2 extra bytes. The container

              * size also cannot be a multiple of the encoded size. */

             if (s->size >= 16 &&
                 (s->data[10] == 0xFE) &&

                 (s->data[11] == 0x00) &&
                 (s->data[12] == 0x00) &&
                 (s->data[13] == 0x06) &&
                 (s->data[14] == 0x00) &&
                 (s->data[15] == 0x00))
                 s->sega_film_skip_bytes = 6;
             else
                 s->sega_film_skip_bytes = 2;
         } else
             s->sega_film_skip_bytes = 0;
     }
 
     s->data += 10 + s->sega_film_skip_bytes;

     num_strips = FFMIN(num_strips, MAX_STRIPS);

     s->frame->key_frame = 0;

     for (i=0; i < num_strips; i++) {
         if ((s->data + 12) > eod)

             return AVERROR_INVALIDDATA;

         s->strips[i].id = s->data[0];

 /* zero y1 means "relative to the previous stripe" */
         if (!(s->strips[i].y1 = AV_RB16 (&s->data[4])))
             s->strips[i].y2 = (s->strips[i].y1 = y0) + AV_RB16 (&s->data[8]);
         else
             s->strips[i].y2 = AV_RB16 (&s->data[8]);
         s->strips[i].x1 = AV_RB16 (&s->data[6]);
         s->strips[i].x2 = AV_RB16 (&s->data[10]);

         if (s->strips[i].id == 0x10)

             s->frame->key_frame = 1;

         strip_size = AV_RB24 (&s->data[1]) - 12;

         if (strip_size < 0)

             return AVERROR_INVALIDDATA;

         s->data   += 12;
         strip_size = ((s->data + strip_size) > eod) ? (eod - s->data) : strip_size;
 
         if ((i > 0) && !(frame_flags & 0x01)) {
             memcpy (s->strips[i].v4_codebook, s->strips[i-1].v4_codebook,
                 sizeof(s->strips[i].v4_codebook));
             memcpy (s->strips[i].v1_codebook, s->strips[i-1].v1_codebook,
                 sizeof(s->strips[i].v1_codebook));
         }
 
         result = cinepak_decode_strip (s, &s->strips[i], s->data, strip_size);
 
         if (result != 0)
             return result;
 
         s->data += strip_size;
         y0    = s->strips[i].y2;
     }
     return 0;
 }
 

 static av_cold int cinepak_decode_init(AVCodecContext *avctx)

 {

     CinepakContext *s = avctx->priv_data;

 
     s->avctx = avctx;

     s->width = (avctx->width + 3) & ~3;
     s->height = (avctx->height + 3) & ~3;

     s->sega_film_skip_bytes = -1;  /* uninitialized state */

     // check for paletted data

     if (avctx->bits_per_coded_sample != 8) {

         s->palette_video = 0;

         avctx->pix_fmt = AV_PIX_FMT_RGB24;

     } else {
         s->palette_video = 1;

         avctx->pix_fmt = AV_PIX_FMT_PAL8;

     }

     s->frame = av_frame_alloc();
     if (!s->frame)
         return AVERROR(ENOMEM);

 
     return 0;
 }
 
 static int cinepak_decode_frame(AVCodecContext *avctx,

                                 void *data, int *got_frame,

                                 AVPacket *avpkt)

 {

     const uint8_t *buf = avpkt->data;

     int ret = 0, buf_size = avpkt->size;

     CinepakContext *s = avctx->priv_data;

 
     s->data = buf;
     s->size = buf_size;
 

     if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)

         return ret;

     if (s->palette_video) {

         const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
         if (pal) {

             s->frame->palette_has_changed = 1;

             memcpy(s->pal, pal, AVPALETTE_SIZE);
         }

     }
 

     if ((ret = cinepak_decode(s)) < 0) {
         av_log(avctx, AV_LOG_ERROR, "cinepak_decode failed\n");
     }

 
     if (s->palette_video)

         memcpy (s->frame->data[1], s->pal, AVPALETTE_SIZE);

     if ((ret = av_frame_ref(data, s->frame)) < 0)

         return ret;

     *got_frame = 1;

 
     /* report that the buffer was completely consumed */
     return buf_size;
 }
 

 static av_cold int cinepak_decode_end(AVCodecContext *avctx)

 {

     CinepakContext *s = avctx->priv_data;

     av_frame_free(&s->frame);

 
     return 0;
 }
 

 AVCodec ff_cinepak_decoder = {

     .name           = "cinepak",

     .long_name      = NULL_IF_CONFIG_SMALL("Cinepak"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_CINEPAK,

     .priv_data_size = sizeof(CinepakContext),
     .init           = cinepak_decode_init,
     .close          = cinepak_decode_end,
     .decode         = cinepak_decode_frame,

     .capabilities   = AV_CODEC_CAP_DR1,

 };